Miees coeyell



M. OORYELL.

STEAM BOILER FURNACE.

(No Model.)

No. 313,992. Patented Mar. 17,1885.

I l/l N. PETERS. Pnowuuw m hn. Washington, DC

ilniTnn STATns PATENT @tricn.

MIERS GORYELL, OF NEW YORK, N. Y.

STEAM-BOILER FURNACE.

SPECIFICATION fcrziing par: of Letters Patent No. 313,992, dated Liar-ch1'7, 1885.

Application filed June 27, 1884. (No model.)

To all whom, it ntcty concern:

Be it known that I, MIERs OoRYELL, of the city and State of New York,have invented an Improvement in Steam-Boiler Furnaces, of which thefollowing is a specification.

In steam-boilers, particularly marine boilers containing horizontaltubes, it is usual to construct the fire-chamber and the flue behind thebridge-wall as wide as possible, in order that the heat may rise aroundthe sides of the boiler nearly as high as the water level. Horizontaltubular boilers of this character are very liable to foam, and manyefforts have been made to check and lessen this difficulty withoutsuccess. In boilers of this character the horizontal tubes are usuallyplaced as closely together as consistent with the requisite strength ofthe tubesheets. I have discovered that the primary cause of the foamingin these steamboilers is the lack of circulation, and the formation ofsteam-bubbles upon the pipes and upon the entire lower surface of theboiler, so that these, rising simultaneously, disintegrate the mass ofwater, and cause the whole to rise as foam, and the water cannotcirculate downwardly again because the tubes are so close togetherthatthey act as a septum to hold up the mass of waterjointly with theupwardly-rushing steam, and previous to the foaming there is such asmallcolumn of water above the tubes that the rush of steam easily lifts thesame.

To insure a rapid circulation of the water in the boiler, and therebycause the circulation to convey with itthe bubbles of steam and throwthem off from the surface, is the object of my improvement.

I have found in practice that when the sides of the fire-chamber aredrawn in, and the line or combustion chamber below the boiler is madesufficiently narrow to lessen the area exposed to the action of bottomheat to about onethird the circumference, then the sides are shielded sofar down that the heat does not cause any ascending columns of water atthe sides of the boiler, but on the contrary allows the water tocirculate downwardly at the sides of the boiler, and to rise near themiddle and pass upwardly and outwardly among the ranges of horizontalfines, and in this manner the efficiency of the boiler is promoted, and

I the difficulty of foaming prevented by concentrating the bottom heatupon a narrower part of the boiler; and this is no injury to the boiler,because the gases passing through the tubes give their heat off to thesurrounding water, which water-takes up the heat more rapidly whencontinuously in contact than it .does when frequently separated by thesteam as the boiler foams.

In the drawings, Figure l is a longitudinal section of the boiler andfurnace. Fig. 2 is a cross-section through the furnace, and Fig. 3

is a sectional plan below the line w 00.

The boiler A is provided with the tubes B and smokeflu'e D, as usual,and the furnace- -dina-ry construction. The sides of. the furnace arecontracted from the grate-bars to the sides of the boiler either at aninclination, as seen at g, or as a segment of an arch, as seen at g, andthe side walls, 71, beyond the bridge-wall 70, come into contact withthe boiler, and are vertical below the said point of contact, so thatthe space between the lines of contact '6 t of the brick-work with thecylindrical shell of the boiler include only about ninety degrees to onehundred and twenty degrees of such cylinder, instead of about onehundred and eighty degrees, as heretofore usual.

The consequence of this mode of constructing the furnace andcombustion-chamber beyond tionsis not exposed to external or bottomheat, and descends as indicated by the arrows, and the water in themiddle part of the boiler ascends and passes outwardly; hence thecirculation is rendered very rapid, and the steam is given off, andfoaming is avoided because the water is compelled to circulate insteadof rising in a mass by the action of the steamgenerator.

In instances where there is a case and vertical tubes inside thewater-space the heat act-s upon the thin layer of water between theboiler-shell and the inner case so that the downward circulation at theboiler-shell is interferred with, and the water is liable to foam. Thesame risk exists where the flues are horizontal and there are waterlegsopening into the sides of the boiler.

I claim as my invention door 0, grate-bars E, and ash-pit F are of oristhat the water in the boiler at the side por- I between the tubes, andthereby prevent f0 inlto ing, substantially as set forth.

Signed by me this 23d day of June, A. D. 1884.

MIERS CORYELI Witnesses:

GEO. T. PINGKNEY, 1 WILLIAM G. MoTT.

